In a modern automobile, a self-locking transmission or braking mechanism is often used to adjust various positions, for example, to adjust the height of a seat.
With respect to a step transmission device used for converting an alternate lifting and lowering movement into an incontinuous rotating movement, various solutions have been proposed in the field of vehicle seat, among which a seizing roller one-way pulley and a pawl braking mechanism are commonly used.
However, the existing pawl braking mechanisms generally have a complicated structure, occupy a large space and mostly adopt a one-way rotating manner. That is to say, if the most suitable height is missed when the height of the seat is adjusted, it is necessary to re-adjust after resetting, causing much trouble.